JPH0212015Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a throw-away cutting tool that is suitable for side milling cutters, groove milling cutters, metal saws, etc., which has a cutting edge on the outer periphery of the cutter body. .

[Conventional technology] Conventionally, the cutting edge shape of the above-mentioned cutting tool was
The flank face and rake face of the cutting edge are formed at a positive angle or a negative angle, and the rake face is formed into a flat plate shape.

Furthermore, as disclosed in Japanese Patent Application Laid-Open No. 48-65578, a chip in which the cutting edge is formed in a convex shape and the rake face is formed so as to swell from the cutting edge toward the center of the chip is used. There are also techniques for cutting by fixing it to various shanks.

[Problems with the Prior Art] However, when cutting is performed using a chip whose "rake face" is flat as described above, the entire cutting edge interferes with the workpiece during initial cutting.
A large cutting force is applied to the cutting edge.

As a result, the cutting edge is prone to breakage and wear, resulting in a shortened lifespan.At the same time, a large cutting load is applied to the cutting edge, making it difficult to obtain a highly accurate cut surface. In case of cutting,
There is also the problem that the workpiece material contacts the cutting edge intermittently, which increases cutting noise and reduces work efficiency.

Furthermore, in order to improve the above-mentioned problems, a tool in which the rake face of the cutting tool has a cylindrical convex curved surface is disclosed in Japanese Patent Publication No. 51-23750.
This is mainly a brazing tool, and when the cutting edge becomes damaged or worn out, it is necessary to remove the tool from the machine tool and perform the specified grinding or replace it with a new tool, which is preferable from the point of view of work efficiency. It cannot be said that it is a formal tool.

In the tool using the chip shown in Japanese Patent Application Laid-Open No. 48-65578, the rake face of the chip is formed to bulge toward the center of the chip, so the chip is placed at a predetermined position on the shank. In the fixed state, the rake face exhibits a negative rake angle, and when cutting with this, the cutting load increases significantly, and together with this, the required horsepower of the machine becomes larger than necessary. At the same time, a large cutting load is applied to the chip itself, so there is a risk of frequent chipping of the cutting edge, and wear is greatly accelerated, making it impossible to achieve high precision on the cut surface.

[Purpose of the invention] The present invention was developed in view of the above-mentioned problems, and has good machinability, minimizes chipping and wear of the cutting edge, and has extremely low noise during cutting. The object of the present invention is to provide a cutting tool suitable for a throw-away type side milling cutter, groove milling cutter, metal saw, etc., which can greatly reduce tool costs.

[Means for Solving the Problems] The present invention solves the above-mentioned problems by the following means.

That is, a mounting surface is formed on the lower surface and a rake surface side is formed on the upper surface, a recess is provided in the center of the rake surface side, and a mounting hole is provided that penetrates from this recess to the mounting surface side. A chip made of a hard material with a curved cutting edge line facing rotationally symmetrically from a flank face with a regular angle and a rake face with a convex shape with a regular angle is attached to the outer periphery of the cutter body. The cutting tool has one cutting edge fixed to a chip seat provided at a predetermined position so as to participate in cutting.

[Operation of the invention] With the above-described configuration, the cutting edge can be formed from a positive flank face and a positive rake face, thereby reducing the cutting load applied to the cutting blade. can be extremely reduced. Moreover, since the cutting edge is formed in a curved shape, cutting starts from a certain point on the cutting edge, and as the cutting progresses, it gradually expands to a cutting edge of a predetermined width. With this, the load applied to the cutting edge during initial cutting can be greatly reduced, and chipping and wear of the cutting edge can be greatly reduced.

Furthermore, since the cutting edges are formed rotationally symmetrically opposed to each other on both sides of the tip, when one of the cutting edges reaches the end of its life, the tip is unfixed and then
Since the tip can be rotated 180 degrees and cutting can be performed using the other new cutting edge, tool costs can be greatly reduced.

[Example] Hereinafter, an example of the present invention will be described based on the attached drawings.

The figures show an example of the throw-away cutting tool of the present invention. Figure 1 is a front view of the side milling cutter with the main part cut out, and Figure 2 is a top view of the side milling cutter shown in Figure 1 with the main part cut out. , Fig. 3 shows the tip used for the side milling cutter shown in Fig. 1, in which a is a front view, b is a top view of a, c is a bottom view of a, d is a right side view of a, e is the left side view of a, etc.

In the above diagram, the cutter body 1 has a mounting hole 1 in the center of the machine tool spindle (not shown).
1, and a wall 1 formed corresponding to the shape of the side surface (flank surface) 21a of the chip 2 at a predetermined position on the outer periphery.
A chip seat 13 having a mounting hole 22 for the chip is formed by arranging the chip seat 13 so that the state in which the chip is attached is staggered in the circumferential direction.
It has a screw hole 14 corresponding to the screw hole 14.

Note that the chip seat 13 having the wall 12 may further be provided with a positioning wall for preventing the chip from moving in the axial direction, but in this embodiment, a pin hole 15 is provided at a predetermined position of the chip seat. and
A positioning pin 3 is inserted into this and fixed, and the axial position of the chip is determined by the pin.

Then, a chip seat 13 having the above-mentioned wall 12 is provided.
Insert tip 2 and tighten tip fixing bolt 4
A chip discharge groove 16 is provided on the front side of the chip in the direction of tool rotation for efficiently discharging chips generated during cutting.

Next, details of the above-mentioned chip 2 will be explained in the third section.

The tip 2 is made of a hard material such as cemented carbide or ceramics, and has a mounting surface 20 corresponding to the tip seat 13 of the cutter body, and
The flanks 21, 21a have a predetermined relief angle θ (0 to 15 degrees, 7 degrees in the example), and a curved surface composed of a part of a cylinder or a cone, and 0 to 20 degrees (10 degrees in the example). )
Cutting edges 24, 24a are formed with rake faces 23, 23a having a rake angle θ ₁ , and the ridge line formed by the above-mentioned flank and rake faces has a predetermined curvature R, Ra.
It is said that

Further, a recess 25 is provided on the rear side of the rake faces 23, 23a, and a mounting hole 22 corresponding to the screw hole 14 of the main body is formed in the center of the recess. A chamfer 2 is provided at the end of the cutting blade 24, 24a to protect the cutting edge and improve strength.
6, 26a are formed at the end on the side not involved in cutting.

As described above, by forming the recess 25 on the rear side of the rake faces 23, 23a, the chips generated along the rake face fall into the recess and are easily crushed and destroyed. This improves discharge performance and workability.

The flank surface formed on the chip as described above;
When a problem occurs with one of the rake faces and cutting edges, the chip is rotated 180 degrees and the cutting edge formed on the other side performs the cutting.

Therefore, the cutting edge is formed rotationally symmetrically as shown in FIG. 3 so that when the tip is rotated 180 degrees, the cutting edge provided on the other side performs a normal cutting action. It is something to do.

[Effects of the invention] As a result of fixing the chip with the above structure to the chip seat of the cutter body 1, attaching this cutter to a machine tool, and cutting the workpiece, the cutting edge involved in the workpiece Since the ridge line and rake face are formed in a curved shape, the cutting edge and rake face that initially contact the workpiece start cutting from a point or a minute surface, and as the cutting progresses, the cutting area expands. This results in a significant cutting force reduction, and at the same time, extremely low cutting noise, significantly reducing chipping and wear of the cutting edge, and improving workability.

In addition, when a problem such as wear or breakage occurs on the cutting edge, or when the tip needs to be replaced, it can be done easily, firmly and accurately, greatly reducing tool costs.

In the embodiments described above, a side milling cutter has been described as an example, but it goes without saying that this can also be used in a cutting tool such as a groove milling cutter or a metal saw having a handle in the center of the cutter body.

[Brief explanation of the drawing]

The figures show an example of the throw-away cutting tool of the present invention. Figure 1 is a front view of the side milling cutter with the main part cut out, and Figure 2 is a top view of the side milling cutter shown in Figure 1 with the main part cut out. , Fig. 3 shows the tip used with the side milling cutter shown in Fig. 1, in which a is a front view, b is a top view of a, c is a bottom view of a, and d is a
e is the right side view of a, e is the left side view of a, etc. 1... cutter body, 2... tip, 3... positioning pin, 4... tip fixing bolt, 21,2
1a... Relief surface, 23, 23a... Rake surface, 2
4, 24a... Cutting edge ridgeline.

Claims (1)

[Scope of utility model registration request] A mounting surface is formed on the lower surface and a rake surface side is formed on the upper surface, a recess is provided in the center of the rake surface side, and a mounting hole is provided that penetrates from this recess to the mounting surface side. A chip made of a hard material with a curved cutting edge line facing rotationally symmetrically from a flank face consisting of an angle and a rake face consisting of a convex and regular angle is inserted at a predetermined location on the outer periphery of the cutter body. 1. A throw-away cutting tool characterized in that the cutting blade on one side is detachably fixed to a tip seat provided at a position so as to participate in cutting.